This invention relates to a new and improved cloth-board reel, and more particularly relates to a new and improved cloth-board reel which reduces the manufacturing costs and provides the required strength.
Originally, it was considered necessary to provide cloth-board reels fabricated of wood in order to provide the required strength to withstand the torsional and buckling stresses imparted during machine-winding of cloth on the reels. In 1966, U.S. Pat. No. 3,286,828, assigned to the assignee herein, was granted for a new and unobvious cloth-board reel which provided the required strength by fabricating the cloth-board reel from an intermediary sheet with a stiffener sheet adhesively secured to each side of the intermediary sheet. The stiffener sheets disclosed in that patent utilized rectangular shaped corrugations to provide the required strength. The rectangular shaped corrugations, having flattened troughs and crests, provided a substantial adhesive area to the intermediary sheet.
The stresses placed upon a cloth-board reel during the machine winding of cloth are substantial. Prior to U.S. Pat. No. 3,286,828, it was not believed possible to make a completely satisfactory cloth-board reel from relatively inexpensive fabricated paper stock, or other suitable inexpensive material. For more than nine years after the invention of the subject matter of U.S. Pat. No. 3,286,828, it was not believed possible to eliminate the intermediate sheet. The substantial expense of providing the intermediary sheet for large numbers of disposable cloth-board reels was very significant. However, in spite of the significant expense of the intermediate sheet, there was no obvious solution to reducing the cost of manufacture. It was felt by those skilled in the art that it was necessary to have the intermediate sheet in order to provide a continuous bond along the corrugations. It was believed that bonding two corrugated sheets directly together, without the intermediate sheet, would be an impossible reliable continuous manufacturing operation. Furthermore, it was believed that bonding two corrugated sheets directly together would not provide the necessary strength to withstand the stresses to which cloth-board reels are subjected in the machine-winding of cloth.
The problem also existed of placing an adhesive on the crest of the corrugations which were to be bound together. In the prior art where an intermediate sheet was used, both sides of the intermediate sheet were provided with an adhesive as disclosed in U.S. Pat. No. 3,510,383, assigned to the assignee herein. All of the problems encountered in attempts to reduce the cost of cloth-board reels made the solution to the problem unobvious.